diff options
Diffstat (limited to 'sql/opt_range.h')
| -rw-r--r-- | sql/opt_range.h | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/sql/opt_range.h b/sql/opt_range.h index 1e3008d78aa..cef9739168f 100644 --- a/sql/opt_range.h +++ b/sql/opt_range.h @@ -457,11 +457,8 @@ public: INDEX MERGE OPTIMIZER Current implementation doesn't detect all cases where index_merge could be used, in particular: - * index_merge will never be used if range scan is possible (even if - range scan is more expensive) - * index_merge+'using index' is not supported (this the consequence of - the above restriction) + * index_merge+'using index' is not supported * If WHERE part contains complex nested AND and OR conditions, some ways to retrieve rows using index_merge will not be considered. The choice |